Ubuntu 有以下libpython3软件包
libpython3-all-dbg
libpython3-all-dev
libpython3-dbg
libpython3-dev
libpython3-stdlib
除了 之外的所有包都是有意义的libpython3-stdlib。包的内容是：
/usr/share/doc/libpython3-stdlib/README.Debian
/usr/share/doc/libpython3-stdlib/changelog.Debian.gz
/usr/share/doc/libpython3-stdlib/copyright
为什么这些文件是单独安装的，而不是作为python3软件包的一部分安装？
答案1
包装libpython3-stdlib作为单独的包允许需要的程序libpython3-stdlib及其依赖项，只需一个命令即可轻松安装它们。Ubuntu apt-cache rdepends libpython3.6-stdlib18.04 中的结果：
$apt-cache 依赖 libpython3.6-stdlib libpython3.6-stdlib 反向依赖： libpython3.6 空闲-python3.6 空闲-python3.6 python3.6 python3-tk python3-tk python3-lib2to3 python3-lib2to3 python3-distutils python3-distutils libpython3.6-最小 libpython3.6-dev libpython3.6-dbg 空闲-python3.6 libpython3-stdlib 空闲-python3.6 python3-distutils python3.6 python3-tk python3-tk python3-lib2to3 python3-lib2to3 python3-distutils libpython3-stdlib libpython3.6-最小 libpython3.6-dev libpython3.6-dbg libpython3.6
这些包都需要 libpython3.6-stdlib，它本身是 libpython3-stdlib 的依赖项。
apt show libpython3-stdlib从Ubuntu 18.04的结果来看：
Python, the high-level, interactive object oriented language, includes an extensive class
library with lots of goodies for network programming, system administration, sounds
and graphics.
This package is a dependency package, which depends on Debian's default Python 3 version
(currently v3.6).
结果apt-cache depends libpython3-stdlib：
libpython3-stdlib 依靠：libpython3.6-stdlib
apt show libpython3.6-stdlib从Ubuntu 18.04的结果来看：
Python is a high-level, interactive, object-oriented language.
Its 3.6 version includes an extensive class library with lots of goodies for
network programming, system administration, sounds and graphics.
This package contains Python 3.6's standard library.
It is normally not used on its own, but as a dependency of python3.6.
结果apt-cache depends libpython3.6-stdlib：
libpython3.6-stdlib
Depends: libpython3.6-minimal
Depends: mime-support
Depends: libbz2-1.0
Depends: libc6
Depends: libdb5.3
Depends: libffi6
Depends: liblzma5
Depends: libmpdec2
Depends: libncursesw5
Depends: libreadline7
Depends: libsqlite3-0
Depends: libtinfo5
Breaks: libmpdec2
Breaks: libpython3.6-testsuite
Breaks: python3-distutils
Breaks: python3-numpy
Breaks: python3-tk
Replaces: libpython3.6-testsuite
Replaces: python3-distutils
答案2
libpython3-stdliblibpython3.6-stdlib是依赖于最新版本的“Python3 标准库”（目前为）的某种虚拟包，包含：
/usr/lib/python3.6/LICENSE.txt
/usr/lib/python3.6/__phello__.foo.py
/usr/lib/python3.6/_compression.py
/usr/lib/python3.6/_dummy_thread.py
/usr/lib/python3.6/_markupbase.py
/usr/lib/python3.6/_osx_support.py
/usr/lib/python3.6/_pydecimal.py
/usr/lib/python3.6/_pyio.py
/usr/lib/python3.6/aifc.py
/usr/lib/python3.6/antigravity.py
/usr/lib/python3.6/asynchat.py
/usr/lib/python3.6/asyncio/__init__.py
/usr/lib/python3.6/asyncio/base_events.py
/usr/lib/python3.6/asyncio/base_futures.py
/usr/lib/python3.6/asyncio/base_subprocess.py
/usr/lib/python3.6/asyncio/base_tasks.py
/usr/lib/python3.6/asyncio/compat.py
/usr/lib/python3.6/asyncio/constants.py
/usr/lib/python3.6/asyncio/coroutines.py
/usr/lib/python3.6/asyncio/events.py
/usr/lib/python3.6/asyncio/futures.py
/usr/lib/python3.6/asyncio/locks.py
/usr/lib/python3.6/asyncio/log.py
/usr/lib/python3.6/asyncio/proactor_events.py
/usr/lib/python3.6/asyncio/protocols.py
...